Modern combine harvester headers, whether for corn, small grain or other crops, can exceed 40 feet in width. With these massive headers mounted to combine harvesters weighing in excess of 30 tons, traveling between five to ten miles per hour during harvesting operations, it has become essential to use header height sensors and header control systems which are properly calibrated in order to avoid the headers from being inadvertently run into the ground when encountering terrain elevation changes, which can result in delays and tens of thousands of dollars in repair costs. Header height sensors and proper calibration of the header control system are even more critical in challenging harvest conditions, such as when harvesting “downed crop,” when it is necessary to run the header close to the ground.
U.S. Pat. No. 7,647,753 (“the '753 patent”) issued to Headsight, Inc., is directed to a system and a method for improving the responsiveness of header height control systems. The '753 patent describes a height sensor disposed with respect to the header to generate a signal varying in magnitude with respect to changes in distance between a pre-established point on the header and the ground. The magnitude of the generated signal when the header is at a predefined set point is determined. For generated signal magnitudes indicating the header is below the set point, the signal magnitudes are operably modified by applying a “gain value.” For generated signal magnitudes indicating the header is above the set point, the signal magnitudes may be modified by applying a different gain value. The application of a gain value or different gain values depending on the height of the header above or below the set point improves the responsiveness of the header height control system to changes in terrain.
While the commercial embodiment of the '753 patent (sold under the trademark Foresight® by Headsight, Inc., 3529 Fir Road, Bremen, Ind. 46506) has enjoyed tremendous commercial success, it has been found that some operators are not taking the time to properly calibrate their header control systems or operators are not properly determining the “gain values” to be applied at the different header heights, thereby adversely affecting the responsiveness of the header control systems to changes in terrain.
Accordingly, there is a need for a system that will automatically and accurately calibrate header control systems to eliminate the need for an operator to manually calibrate the header control system and to avoid operator errors. Furthermore, there is a need for a system that will provide feedback to the operator to ensure the quality of the calibration and to assist the operator in identify potential problems with sensors or header setup which could cause calibration errors or imprecise calibrations.